The present invention relates to a repeating apparatus for use in a CDMA (Code Division Multiple Access) communications system, and, more particularly, to a repeating apparatus for providing call service to a mobile telephone located within a shadow area such as a building and a underpass by using a telephone line within the building and a dedicated line (e.g., underground telephone line) connected to a dedicated line network.
Generally, a telephone line currently used seems improper to bandwidth communications, e.g., CDMA (Code Division Multiple Access) communications, because of its high RF transmission loss and non-uniform characteristics.
Furthermore, conventionally, when a mobile phone such as cellular phone or a PCS phone using the CDMA technique is located at a shadow area like a building or a underpass, an optical cable or a RF coaxial cable within the building is used to repeat a communication signal.
However, in the conventional method, the expensive optical cable or a RF coaxial cable is required, it costs much. Especially, if the optical cable or the RF coaxial cable for providing the call service to the mobile phone is not installed initially within the building, interior of the building may be disassembled to install the optical cable or the RF coaxial cable so that manpower and time could give rise to a problem.
Therefore, it is an object of the present invention to provide a repeating apparatus for providing call service to a mobile telephone positioned within a shadow area like a building by using a telephone line within the building.
And, it is another object of the present invention to provide a repeating apparatus for providing call service of high quality to a mobile telephone and preventing a call drop during a call by transmitting, via a dedicated line connected to a dedicated line network, a high power signal to a local shadow area out of a building at which a mother station is positioned.
In accordance with an aspect of the present invention, there is provided a repeating apparatus including: at least one first and second child stations; and a mother station within a base station, wherein, depending on a synchronization signal generated by a synchronization signal generator in the base station, the mother station combines data signals transferred from a mobile switching center to generate an intermediate frequency signal to transfer to an unused telephone line; and converts the intermediate frequency signal transferred through the unused telephone line to a baseband signal to transfer to the mobile switching center, and the intermediate frequency signal is transceived through the unused telephone line between the mother station and at least one first child station.